The present invention relates to a fastening or fixing device and a tool for securing the same.
Dependent on its utilization, a fixing device may in one a form include a clamping sleeve for fixing cog wheels, coupling halves, inner rings of roller bearings, and the like on shafts, for joining shafts or pipes, connecting pipes in T-joints, attaching a tool to a machine, etc., and may, in a second form include a nut for use on a non-threaded bolt.
The methods most well-known today for fixing wheels, coupling halves, and the like on shafts include use of keys, adapters, like "Taper Locks", and shrinking. The first mentioned method is labor consuming, and requires cutting wedge-shaped grooves in the shaft as well as in the wheel, whereas the second requires much space as well as being labor consuming, although it is a simple method in case of replacement or maintenance. The third method mentioned above, i.e. shrinking, is the method requiring least space. On the other hand, this method demands great accuracy in processing as well as special procedures, like heating/cooling in connection with mounting operations which are, thus, typically carried out in a workshop.
Screws and nuts are well-known fixing devices and are widely used in present technical equipment, but nuts and threads also have other uses than this conventional one, e.g. a nut may be used for locking a roller bearing on a shaft.
When the mentioned fixing devices are secured it is important to ensure clamping in a controlled and reliable manner. A clamping sleeve used as a structural member represents a novelty. Practical tests, however, have shown that the conventional hexagonal design of nuts provides an unsuitable wrench mount for sleeves, and the same is the case for hook wrenches. Such wrench mounts require too much axial space and/or too much thickness of sleeve material to be useful in practical cases.
It is, thus, desirable to develop new kinds of fixing devices which are especially useful for thin sleeves, like the clamping sleeve mentioned above, but also for the kind of nuts comprised by the present invention.